Els van Meijel

44 Chapter 3 | Acute pain and posttraumatic stress symptoms Measures Acute pain At the first assessment we asked children to rate the worst pain since the accident. For this purpose, we used the Visual Analogue Scale (VAS), a small ruler with a 10-cm line, marked with “no pain” on the left, and “the worst possible pain” on the right. The children used a sliding gauge to mark the location corresponding to the amount of pain they had experienced. The reverse side of the instrument shows the corresponding values from 0 to 100 mm. This instrument was used according to internal hospital guidelines (Baas & Kramer, 2008). In the analyses we used the total pain score; a higher score indicates greater pain intensity. Scores can also be rounded to the nearest integer and categorized as no or mild pain (0–3), moderate pain (4–7), and severe pain (8–10). We used these categories to describe the distribution of pain severity in the sample and to examine associations with severity of posttraumatic stress per category. Posttraumatic stress Three months after the accident, children completed the Dutch version of the Children’s Revised Impact of Event Scale (CRIES; Children and War Foundation, 1998; Olff, 2005; Verlinden et al., 2014). The Dutch version of the English CRIES was obtained through a standard forward–backward translation procedure by independent health professionals ((Verlinden et al., 2014). This self-report measure is based on the definition of PTSD according to DSM-IV-TR criteria and gives a good indication of the presence of PTSD (APA, 2000; Verlinden et al., 2014). It consists of 13 questions in the subscales re- experiencing, avoidance and hyperarousal, with answers on a 4-point scale. Examples of typical CRIES items are: “Do you startle more easily or feel more nervous than you did before it happened?” and “Do pictures about it pop into your mind?”. We asked the children to focus on their accident when answering the questions. Items are rated according to the frequency of their occurrence during the past week ( Not at all =0, Rarely =1, Sometimes =3 and Often =5). The Dutch CRIES is an effective and valid tool for screening of PTSD and shows moderate to good reliability: Cronbach’s alpha for the total score is .89 and for the subscales of re-experiencing, avoidance and hyperarousal .82, .77 and .74, respectively (Verlinden et al., 2014). In the current study, we used the CRIES total score. The total score can range from 0 to 65, and is an indicator of the child’s perception of posttraumatic stress; a higher total score indicates higher severity.